This invention is in the field of cultivators and seeders such as are used in agriculture for seeding, fertilizing, and the like by opening furrows in the ground and depositing appropriate agricultural materials in the furrows, and in particular with mechanisms to close the furrows created by such seeders.
Seeders are known in the agricultural industry for planting and fertilizing crops. A typical seeder comprises a frame on wheels carrying a plurality of furrow openers and a distribution system for depositing agricultural materials such as seed, fertilizer, and the like in the furrows. Typically there will also be a packing mechanism as well that will pack the furrows to improve seed to soil contact.
Commonly the furrow opener comprises a ground engaging tool such as a knife, shovel, or the like mounted on a shank that extends downward from the seeder frame, and a tube that delivers agricultural materials into the furrow created by the tool as it moves through the ground. Some of the soil moved by the tool to create the furrow will fall back into the furrow to cover the seed, however typically a significant amount of soil remains in a pair of ridges, one on each side of the furrow. Considerable prior art has been directed to creating furrow closing devices for moving this soil back over the furrow to ensure that the agricultural materials in the furrow are covered, and to level the ground.
U.S. Pat. Nos. 5,782,307 to Forsyth, 5,623,997 to Rawson et al., 5,595,249 to Steinberger et al., 5,333,694 to Roggenbuck et al., 4,485,878 to Uken, and 2,070,509 to Chiles disclose furrow closing devices comprising a pair of discs mounted to a shank and oriented to move soil from a location beside a furrow over on top of the furrow. The discs can be pivotally mounted to the shank and biased downward as disclosed in Forsyth and Rawson et al. to ensure they engage the soil. Alternatively the weight of the pivotally mounted discs can suffice to engage the soil sufficiently for the purpose of moving the required amount of soil, as disclosed in Steinberger et al., and Chiles.
Similarly U.S. Pat. Nos. 2,805,613 to Siems, 3,157,139 to Spindler, 3,175,622 to Stam, 3,227,226 to Bayne, 3,251,423 to McCauley, 3,322,203 to Johnson, 3,536,145 to Clark, and 4,037,545 to Dreyer disclose furrow closing and ground leveling devices comprising various drags, scoops, harrow teeth, and the like that are fixed to the shanks to push soil toward the furrow.
In typical air seeders, one or more hoses run down the back of the shank to direct agricultural materials into the furrow created by the ground engaging tool on the bottom of the shank. The prior art devices generally are mounted on the rear of the shank, and so it is difficult to properly locate the hoses and devices on the rear of the shank.
Furrow closers that move soil with drags do not work well in wet, sticky soil because the soil builds up on the surface of the drag. Harrow teeth do not move sufficient soil to satisfactorily cover the furrow, since such teeth push soil contacted in both directions, rather than moving soil only toward the furrow, as with a drag. Soil does not stick to rotating discs to the same extent, and scrapers can be attached to clean disc surfaces as they rotate. The prior art disc furrow closers are complex and costly, especially those that include a spring to bias the discs.
On farms where cattle are fed on fields, baler twine is often present on land being worked by air seeders and the like. When using ground engaging rotating discs such as are used in the furrow closers described above, such twine commonly wraps around the shaft connecting the discs to the implement. This ball of twine exerts considerable pressure and can cause the disc to stop rotating and can damage bearings. It is common to cut this wrapped twine away with a cutting torch, however it is difficult to prevent damaging the bearings and shaft when cutting twine wrapped tightly against them.